The present invention relates to a device having an orifice covered by an optical device in the shape of a disk of glass or a lens, which is intended for being exposed to dirtying reducing the transparency, which dirtying may be for all splash of liquid.
Such devices are frequent in connection with operarating instruments for among others the more and more common so called laparotomy, and in fiber optical equipment. The use of such instruments and equipment is made difficult, however, when the optical device becomes dirtied by for example blood or other body fluids during surgical operations or medical examinations.